ABOUT ME

I came to the U.S. at age of 12 with my mother. We settled in sunny Florida, which was quite a contrast to Minsk. I have always been fascinated by sex and relationships. If you have a question about sex that you prefer not to post in the comments, you can email me at svetlanaivano(at)yahoo.com.

Your Friday Pleasure Post at Exploring Intimacy tells where the most sensitive part of the clitoris is and how to stimulate it.

… There are tons of different techniques for stimulating a clitoris, far too many for me to put into one post. But what I will tell you now is that for most women the most sensitive part is the underside of her clit! Read more

Estrus , or oestrus as the British spell it, is “heat”. When a female cat or mare or female chimp ovulates, they go into heat . That means the female becomes sexually excited and will mate with any male of her species that is proximate.

Chimpanzees have a promiscuous model for mating. The males take turns having sex with the estrus female.

In Gorillas , the dominant silverback chases away rival males so as to keep the estrus female for himself.

Placental mammals are also called “eutherians”. We are placental mammals. We have a placenta . Kangaroos do not.

Placental mammals also have a pelvis which is different from that of a opossum, dinosaur, bird, or frog. We have a “closed pelvis”. The bones come together at the front, at the “pelvic symphysis”. It is
like a closed ring of bone, containing the reproductive organs and the lower intestines.

One definition of humans states that we are a primate that lacks estrus. This means when women ovulate, they do not go into heat like other eutherians. A woman who is ovulating might
want sex more than at other times in her cycle, but she still can say “No”.

This is important. It means a woman can pick and choose who she will mate with. This is called “female choice” and is part of Darwin’s explanation of Sexual Selection. He had two brilliant
ideas: Natural Selection and Sexual Selection. Sexual Selection is
much more subtle than Natural Selection .

Natural Selection eliminates weak traits. In Sexual Selection one or the other of the two sexes, chooses a mate based on some criteria.

Most Sexual Selection is female Choice. In the Galapagos, Darwin saw finches that varied from island to island. After pondering the observations for many years, he realized that the female finches had chosen, over time, male finches which had certain traits that made them more successful in particular environments.

Geographic isolation plus female choice equals diversity .

Cottontail rabbits have estrus. The female will mate with any male that is proximate. This makes for a lack of diversity. A cottontail from Maine will look like a cottontail from Mexico.

If all the dogs in the world were free to breed naturally, there would eventually be a single generic dog.

Women exercise Female Choice. All the variety in appearance of humans is the result of this. Redheads and blonds exist because somewhere in time, women preferred red haired or blond men.

To recapitulate, because women lack estrus, there is diversity in appearance.

How then, did we lose estrus?

200,000 years ago, in Africa, there were bands of H.erectus homonids. They looked much like us and even their brains were within the range of modern humans. But they weren’t human.

How do we know? Because they had been around for millions of years and never progressed beyond the hand axe. The hand axe is a sharp stone used to kill antelope or cut up meat.

One of these female H.erectus gave birth to a daughter that was different. The daughter, when she reached puberty, did not go into heat when she ovulated. This “Eve” was the first H.sapiens and H.sapiens are primates in which the female does not have estrus.

How do we know that her mother had estrus?

Because for 150 million years there were eutherians and 99.99% of eutherians have estrus.

All our close primate relatives have estrus. Women do not.

In the H.erectus band, the females went into heat when they ovulated. A male merely had to be nearby and he would have sex with estrus females.

This was not the case with Eve.

When she was about 12 and first ovulated, she might have felt a desire for sex, but not to the degree that her body forced her into mating. The males in the band knew that she was ovulating because they could scent her condition.

No matter how long the males waited, Eve did not go into heat.

One consequence of Eve’s freedom from estrus compulsion was the development of language. Imagine a male sitting patiently, waiting for her to go into estrus. Like males of many species, the H.erectus would fidget and make vocalizations. Perhaps one particular noise attracted her attention, causing Eve to look up.

Serendipitously, he repeated the sound.

Eve smiled.

In that instant, human language was born.

This is male vocalization used to court the female.

Exactly the same process happens with birds, which also lack estrus. The male bird vocalizes for the female. If she approves of his songs they form a pair bond. 92% of all bird species form the same type of pair bonds as are formed by humans.

Adult birds teach baby birds to sing. They also teach them to use vocalization to communicate. Baby birds learn to know which sounds mean “food” and which mean “danger”.

Humans teach infants to vocalize. We teach them to recognize words and to produce words. We teach them language in the same way as birds are taught language. Like birds, our brains have two halves. In one half we receive sounds while the other side produces sounds. Hearing and vocalization.

Our consciousness exists in the hippocampus; the referee between the two halves.

Our consciousness sits there sorting through words. We think in words. When strung together they form thoughts.

Teaching the baby to talk hard wires its plastic brain to make it more efficient. It thinks better, like the tiny bird brain.

Other eutherians have overly large brains which do not think as well. Birds think with those elegant little bird brains. Dinosaurs had elegant little bird brains. They did not need the big mammalian brain . Baby dinosaurs learned to vocalize and their brains thus became elegant.

H.erectus inherited 150 million years of ever-larger mammalian brain because
it needed it to make up for a lack of elegance.

But where did estrus go?

The loss of estrus resulted from a very small change in the pelvic floor of the female.

In most eutherians, the female has, in her clitoris, “vestibular bulbs”.These are small bodies that swell up with blood at ovulation and put pressure on the “glans clitoridis”. In the glans are
encapsulated nerve endings called “Pathian bodies”. They respond to changes in pressure. They are the same in the male “glans penis” as well as in the female glans.

When orgasm occurs, the blood pressure in penis and clitoris spikes. That stimulates the Pathian bodies and gives the pleasurable feelings.

The swelling of the vestibular bulbs works just like orgasm, putting pressure on the glans clitoridis and making the female sexually excited.

Could estrus excitement be due to testosterone, the only homone of desire? No, since the estrus female
has LOWER levels of testosterone than she does at other times in her fertility cycle.

A woman with a pituitary tumor has excessive testosterone. She becomes hypersexual but she is still able to refuse to mate.

The vestibular bulbs in Eve were displaced about 5 cm from their probable location in her mother.

In Eve, as in other women, these bulbs now reside along the urethra, near where it exits the body.

This hypothesis begs the question “Why has the relationship of estrus with human traits not been previously discovered?”

The answer is found in one word: sex. Any researcher into human sexuality has to face a nearly insurmountable wall of ridicule. Kinsey was an excellent example.